immediately cleared seven rooms, started taking care of the patients. it all happened they quickly. they also confirmed, john, you may know this by now, in these types of injuries you often see a lot of debris, shrapnel-type wounds, but they did confirm now that the type of shrapnel that they saw could not have just been debris lying around but rather carpenter nails and bb-like objects as they were described they found. and doctors are confident now that those were actually within the devices and intended to be part of the injury that was sort of seen here. also at children's hospital, as you may know, john, ten patients were taken there, boston children's. two were adults, eight children. three remain in the hospital, two in critical condition. but many of the patients are being discharged. a little bit of good news there, john. >> reporter: all right, it dr. sanjay gupta, dr. shah, thank you for being with us.